Receiving device, receiving method, program, and broadcasting system

ABSTRACT

Disclosed herein is a receiving device for receiving AV contents, the receiving device including: an obtaining section configured to obtain a description document described in a program language for displaying contents from a server present on a network connected with the receiving device; a determining section configured to determine whether the obtained the description document is obtained from a first server managed on a broadcaster side broadcasting the AV contents; and a controlling section configured to control execution of the obtained the description document according to a result of determination by the determining section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/980,917, filed Dec. 29, 2010, which is related to and claims priorityunder 35 U.S.C. §119(e) to Provisional Application Ser. No. 61/378,277,filed Aug. 30, 2010, the contents of which are hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a receiving device, a receiving method,a program, and a broadcasting system, and particularly to a receivingdevice, a receiving method, a program, and a broadcasting systemsuitable for use in executing data broadcasting contents in such amanner as to be interlocked with the progress of AV contentscorresponding to a so-called program in digital television broadcasting,for example.

2. Description of the Related Art

In Japan, the digitization of television broadcasting has been promoted,and terrestrial digital broadcasting, BS digital broadcasting and thelike have been spread. In addition, in digital television broadcastingsuch as terrestrial digital broadcasting, not only broadcasting of AVcontents corresponding to a so-called program but also data broadcastingusing BML (Broadcast Markup Language) have been realized (see JapanesePatent Laid-Open No. 2003-131981, for example).

A television receiver receiving data broadcasts can for example displayinformation related to a program (AV contents) being broadcast, displayinformation unrelated to the program being broadcast (a notice ofanother program, news, a weather forecast, traffic information and thelike), and execute an application program interlocked with the program(AV contents) being broadcast.

In addition, the above-described television receiver is configured tobehave differently in a case of realizing service managed on abroadcaster side performing digital television broadcasting (for examplethe service of displaying a weather forecast by data broadcasting) and acase of realizing service not managed on the broadcaster side (forexample the service of being connected to the Internet and displaying ahome page or the like).

Specifically, when a weather forecast is displayed in data broadcastingas service managed on the broadcaster side, for example, a readingprocess for reading area information indicating a place of residence ofa user which area information is already registered in the televisionreceiver is performed to display the weather forecast corresponding tothe place of residence of the user.

On the other hand, when connection to the Internet is established and ahome page or the like is displayed as service not managed on thebroadcaster side, for example, the above-described reading process orthe like is not allowed to be performed so as to prevent processesunintended by the user (area information is illegally read and notifiedto a malicious third party, for example) from being performed.

Also in Europe, broadcasting corresponding to data broadcasting in Japanhas been realized by DVB-MHP (digital video broadcasting-multimedia homeplatform), which defines description, a distributing system of databroadcasting contents and the like.

SUMMARY OF THE INVENTION

Digital television broadcasting in the U.S. is expected to realizeservice corresponding to data broadcasting in digital televisionbroadcasting in Japan by obtaining an HTML document described in HTML(Hyper Text Markup Language) from a server managed on a broadcaster sideand executing the HTML document in ATSC (Advanced Television SystemsCommittee) 2.0.

If service is realized by using an application program composed ofresources representing video, audio, still images and the like(corresponding to MPEG, MP3, and JPEG in FIG. 1) and a script (executioncode) referring to the resources and performing a predetermined processas shown in FIG. 1, an operation mode can be set for each applicationprogram, and a specific process such as a reading process or the likecan be allowed (or limited) according to the set operation mode.

Specifically, for example, an operation mode allowing (not limiting)performance of the specific process is set for an application programobtained from a server managed by a broadcaster. Then, it suffices toset an operation mode not allowing (limiting) performance of thespecific process for an application program obtained from a server onthe Internet which server is not managed by the broadcaster.

Incidentally, the application program as shown in FIG. 1 includes forexample an application program created in Java language or the like andcomposed of a plurality of class files (script) and resources (video,audio, still images and the like) of a file structure referred to asjar.

When an application program is composed of resources and a script asshown in FIG. 1, there is a clear boundary between application programs.Therefore an operation mode can be set for each application program toallow (or limit) a specific process (reading process or the like).

When an HTML document planned in digital television broadcasting in theU.S. is used, on the other hand, the setting of an operation mode as inthe case of the application program shown in FIG. 1 cannot be made.

Specifically, for example, when service is realized by using an HTMLdocument, a transition is sequentially made to HTML documents to beexecuted, and each HTML document is executed independently, instead ofone application program being executed as shown in FIG. 1.

It is therefore not possible to treat each HTML document executedindependently when realizing service as one application program and setan operation mode.

Thus, when the HTML document planned in the U.S. is used, it is notpossible to allow (or limit) a specific process according to anoperation mode, and a process unintended by a user may occur.

The present invention has been made in view of such a situation. It isdesirable to prevent a process unintended by a user from being performedeven when service for data broadcasting is realized through documenttransitions. According to a first embodiment of the present invention,there is provided a receiving device for receiving AV contents, thereceiving device including: obtaining means for obtaining a descriptiondocument described in a program language for displaying contents from aserver present on a network connected with the receiving device;determining means for determining whether the obtained descriptiondocument is obtained from a first server managed on a broadcaster sidebroadcasting the AV contents; and controlling means for controllingexecution of the obtained description document according to a result ofdetermination by the determining means.

The receiving device can further include extracting means for extractingtrigger information relating to the description document executed so asto be interlocked with progress of the AV contents from the AV contents,wherein the obtaining means can obtain a description document from thefirst server on a basis of the trigger information, and obtain adescription document from a second server not managed on the broadcasterside in response to a user operation.

The determining means can determine whether the obtained descriptiondocument is obtained from the first server on a basis of whether firstidentifying information for identifying the first server and secondidentifying information for identifying the server as an obtainingdestination from which the description document is obtained coincidewith each other.

The receiving device can further include determining means fordetermining that identifying information for identifying an obtainingdestination of a first description document executed so as to beinterlocked with progress of the AV contents is the first identifyinginformation.

The receiving device can further include executing means for executingthe obtained description document, wherein the controlling means canmake the executing means operate in a first management mode allowing apredetermined specific process to be performed by executing thedescription document when the determining means determines that thedescription document is obtained from the first server managed on thebroadcaster side, and the controlling means can make the executing meansoperate in a second management mode not allowing the predeterminedspecific process to be performed by executing the description documentwhen the determining means determines that the description document isnot obtained from the first server managed on the broadcaster side.

When the executing means operates in the first management mode, thedetermining means can determine each time a description document isobtained whether the obtained description document is obtained from thefirst server, and the controlling means can change the executing meansfrom the first management mode to the second management mode and makethe executing means operate in the second management mode in response todetermination by the determining means that the description document isnot obtained from the first server.

When the executing means operates in the second management mode, thecontrolling means can change the executing means from the secondmanagement mode to the first management mode and make the executingmeans operate in the first management mode in response to determinationby the determining means that the description document is obtained firstfrom the first server.

According to the first embodiment of the present invention, there isprovided a receiving method of a receiving device for receiving AVcontents, the receiving method including: by the receiving device, anobtaining step of obtaining a description document described in aprogram language for displaying contents from a server present on anetwork connected with the receiving device; a determining step ofdetermining whether the obtained description document is obtained from afirst server managed on a broadcaster side broadcasting the AV contents;and a controlling step of controlling execution of the obtaineddescription document according to a result of determination in thedetermining step. According to the first embodiment of the presentinvention, there is provided a program for controlling a receivingdevice for receiving AV contents, the program making a computer of thereceiving device perform a process including: an obtaining step ofobtaining a description document described in a program language fordisplaying contents from a server present on a network connected withthe receiving device; a determining step of determining whether theobtained description document is obtained from a first server managed ona broadcaster side broadcasting the AV contents; and a controlling stepof controlling execution of the obtained description document accordingto a result of determination in the determining step.

According to the first embodiment of the present invention, adescription document described in a program language for displayingcontents is obtained from a server present on a network connected withthe receiving device, whether the obtained description document isobtained from a first server managed on a broadcaster side broadcastingthe AV contents is determined, and execution of the obtained descriptiondocument is controlled according to a result of the determination.

According to a second embodiment of the present invention, there isprovided a broadcasting system including: a transmitting device fortransmitting AV contents; and a receiving device for receiving thetransmitted AV contents; the transmitting device including transmittingmeans for storing, in the AV contents, trigger information relating to adescription document described in a program language for displayingcontents, the description document being to be executed by the receivingdevice so as to be interlocked with progress of the AV contents, andtransmitting the AV contents from a server present on a networkconnected with the receiving device; and the receiving device includingextracting means for extracting the trigger information from the AVcontents, obtaining means for obtaining a description document from afirst server managed on a broadcaster side broadcasting the AV contentson a basis of the extracted trigger information and obtaining adescription document from a second server not managed on the broadcasterside in response to a user operation, determining means for determiningwhether an obtained description document is obtained from the firstserver, and controlling means for controlling execution of the obtaineddescription document according to a result of determination by thedetermining means.

According to the broadcasting system according to the second embodimentof the present invention, the transmitting device stores, in the AVcontents, trigger information relating to a description documentdescribed in a program language for displaying contents, the descriptiondocument being to be executed by the receiving device so as to beinterlocked with progress of the AV contents, and transmits the AVcontents from a server present on a network connected with the receivingdevice, and the receiving device extracts the trigger information fromthe AV contents, obtains a description document from a first servermanaged on a broadcaster side broadcasting the AV contents on a basis ofthe extracted trigger information and obtains a description documentfrom a second server not managed on the broadcaster side in response toa user operation, determines whether an obtained description document isobtained from the first server, and controls execution of the obtaineddescription document according to a result of determination by thedetermining means.

According to the present invention, it is possible to prevent a processunintended by a user from being performed even when service for databroadcasting is realized through document transitions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example of an application programcomposed of resources and a script;

FIG. 2 is a block diagram showing an example of a broadcasting systemaccording to an embodiment of the present invention;

FIG. 3 is a diagram showing an example of display of a screen displayedon a monitor by a receiving device;

FIG. 4 is a diagram of assistance in explaining an outline of thepresent invention;

FIG. 5 is a block diagram showing an example of configuration of thereceiving device;

FIG. 6 is a diagram showing a concept in a case where triggerinformation is stored and transmitted in PCR packets of a TS;

FIG. 7 is a diagram showing a position where trigger information isstored in a PCR packet;

FIG. 8 is a diagram showing an example of information items included intrigger information;

FIG. 9 is a diagram showing an example of syntax of trigger information;

FIG. 10 is a flowchart of assistance in explaining a trigger informationcorresponding process performed by the receiving device;

FIG. 11 is a diagram showing an example of transitions of a screen whena data broadcasting HTML document is executed so as to be interlockedwith the progress of a television program;

FIG. 12 is a diagram showing an example of transitions of a screen whena data broadcasting HTML document not involving screen display isexecuted so as to be interlocked with the progress of a televisionprogram;

FIG. 13 is a diagram showing an example of a life cycle of a databroadcasting HTML document;

FIG. 14 is a diagram showing an example in which a transition is madefrom a TDO active operation state to a Web active operation state;

FIG. 15 is a flowchart of assistance in explaining a management modesetting process performed by the receiving device;

FIG. 16 is another diagram showing an example of a life cycle of a databroadcasting HTML document;

FIG. 17 is another diagram showing an example of information itemsincluded in trigger information; and

FIG. 18 is a block diagram showing an example of configuration of acomputer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 1. Embodiment [Exampleof Configuration of Broadcasting System]

FIG. 2 shows a broadcasting system 1 according to an embodiment of thepresent invention. The broadcasting system 1 includes a broadcastingdevice 11 and a server 12 provided on a broadcaster side and a receivingdevice 30 provided on a receiver side.

Incidentally, a point of the present invention is that a specificprocess realized by the execution of an HTML document is allowed (orlimited) according to whether the HTML document obtained via theInternet 20 and executed in the receiving device 30 is managed on thebroadcaster side.

Specifically, for example, when the receiving device 30 executes an HTMLdocument managed on the broadcaster side (for example an HTML documentobtained from the server 12 provided on the broadcaster side), theperformance of a specific process by the HTML document is allowed (notlimited).

Conversely, when the receiving device 30 executes an HTML document notmanaged on the broadcaster side (for example an HTML document obtainedfrom a server not managed on the broadcaster side but connected to theInternet 20), the performance of a specific process by the HTML documentis not allowed (is limited). Details of the point of the presentinvention will be described later with reference to FIG. 4.

The broadcasting device 11 transmits (broadcasts) a digital televisionbroadcast signal. Suppose that the broadcasting band of the digitaltelevision broadcast signal is occupied by a band for video, a band foraudio, and a band for control information, and that no band fortransmitting contents for data broadcasting is provided.

In addition, in predetermined timing, the broadcasting device 11 storesand transmits trigger information in a packet including PRC (ProgramClock Reference) (which packet will hereinafter be referred to as a PCRpacket) among TS (Transport Stream) packets forming a TS of the digitaltelevision broadcast signal.

The trigger information in this case is composed of informationindicating timing of execution of a data broadcasting HTML documentrepresenting an HTML document to be executed to realize service for databroadcasting, information indicating a destination from which to obtainthe data broadcasting HTML document, and the like. Details of thetrigger information will be described later with reference to FIGS. 6 to9.

The server 12 is managed on the broadcaster side. The server 12 suppliesthe data broadcasting HTML document or the like according to a requestfrom the receiving device 30 accessing the server 12 via the Internet20.

The receiving device 30 receives the digital television broadcast signaltransmitted from the broadcasting device 11, obtains the video and audioof AV contents corresponding to a television program, and outputs thevideo to a monitor (not shown) and outputs the audio to a speaker (notshown).

In addition, the receiving device 30 accesses the server 12 via theInternet 20, and obtains and executes the data broadcasting HTMLdocument. Thereby, as shown in FIG. 3, the receiving device 30 displaysvideo 43 obtained by superimposing the video 42 of data broadcastingcontents on the video 41 of the AV contents on the monitor not shown inthe figure.

Incidentally, the receiving device 30 may be present as a discrete unit,or may be built into a television receiver or a video recorder, forexample. A detailed configuration of the receiving device 30 will bedescribed later with reference to FIG. 5.

[Outline of the Present Invention]

Next, FIG. 4 shows an outline of the present invention.

The receiving device 30 displays the video 43 as shown in FIG. 3 on thebasis of trigger information included in the digital televisionbroadcast signal transmitted from the broadcasting device 11.

Specifically, for example, the receiving device 30 displays the video 43as shown in FIG. 3 on the monitor not shown in the figure by obtaining adata broadcasting HTML document (corresponding to a Liner TV TDO contenton the Internet in FIG. 4, for example) from the server 12 and executingthe data broadcasting HTML document in response to reception of triggerinformation (corresponding to Trigger “Start” from the air in FIG. 4,for example) from the broadcasting device 11, or executing a databroadcasting HTML document (corresponding to a Liner TV TDO content in aFile system in FIG. 4, for example) obtained from the server 12 inadvance and already stored.

In addition, for example, when a program is viewed on the receivingdevice 30 using download broadcasting, which receives and stores theprogram (digital television broadcast signal) from the broadcastingdevice 11 in advance and reproduces the stored program in response to anoperation of a user, the receiving device 30 displays the video 43 asshown in FIG. 3 by obtaining a data broadcasting HTML document(corresponding to an NRT TDO content in FIG. 4, for example) from theserver 12 and executing the data broadcasting HTML document in responseto obtainment of trigger information (corresponding to Trigger “Start”from the Video files that is played by local player in FIG. 4, forexample) included in the stored program, or executing a databroadcasting HTML document (corresponding to NRT TDO in FIG. 4, forexample) obtained from the broadcasting device 11 in advance and alreadystored by download broadcasting.

Incidentally, in this case, suppose for example that a driver (face)displayed as video 42 shown in FIG. 3 is provided with a link to a homepage of the driver, and is selectable by a user.

When a user operation of selecting the driver on the video 42 in FIG. 4is performed, the receiving device 30 displays the home page of thedriver and the like on the monitor not shown in the figure by obtainingan HTML document for the home page (Generic Web Content in FIG. 4, forexample) from a server other than the server 12 and executing the HTMLdocument. Incidentally, the HTML document for the home page representsan HTML document retained by a server not managed on the broadcasterside (server different from the server 12).

When the receiving device 30 executes a data broadcasting HTML document,the receiving device 30 needs to be able to perform a specific processnecessary to enhance service for data broadcasting.

Specifically, for example, when a weather forecast corresponding to aplace of residence of the user is displayed on the receiving device 30as service for data broadcasting, the data broadcasting HTML documentneeds to perform for example a process of reading area informationindicating the place of residence of the user, which area information isalready registered in the receiving device 30, as the specific process.

On the other hand, when a home page or the like is displayed on thereceiving device 30, for example, it is not desirable for the specificprocess to be performed by the HTML document for the home page.

Specifically, when a home page or the like is displayed, for example, anHTML document for the home page is obtained from a server not managed onthe broadcaster side, and executed. In this case, unlike the server 12managed on the broadcaster side, the server not managed on thebroadcaster side may have an HTML document for the home page which HTMLdocument is created by a malicious third party (for example an HTMLdocument performing a process of illegally reading the area informationregistered in the receiving device 30 and supplying the area informationto the server).

Accordingly, a management mode is set in the receiving device 30 suchthat the specific process can be performed on the left side of aboundary line (represented by a thick line) shown in FIG. 4 and suchthat the specific process cannot be performed on the right side of theboundary line. The receiving device 30 allows (or limits) the specificprocess to be performed by an HTML document according to the setmanagement mode.

Incidentally, the specific process refers to a process that causes adisadvantage to the user when illegally performed by a malicious thirdparty (for example a process of illegally obtaining the personalinformation or the like of the user, thus threatening the security ofthe user).

The specific process is for example defined in advance by a user, acompany that manufactures the receiving device 30, or the like.Incidentally, the specific process includes not only the above-describedreading process but also for example a channel selecting process forselecting a channel, a recorder operating process for making thereceiving device 30 perform recording or the like when the receivingdevice 30 functions as a video recorder, an obtaining process forobtaining program information related to a program on a channel beingselected, and a bookmark control process for bookmarking a predeterminedURL

(Uniform Resource Locator). [Example of Configuration of ReceivingDevice 30]

FIG. 5 shows an example of configuration of the receiving device 30. Thereceiving device 30 includes a tuner 61, a demultiplexing section 62, anaudio decoder 63, an audio outputting section 64, a video decoder 65, atrigger detecting section 66, a video outputting section 67, acontrolling section 68, a memory 69, an operating section 70, arecording section 71, a communication I/F 72, and a browser 73.

The tuner 61 receives and demodulates a digital television broadcastsignal corresponding to a channel selected by the user, and outputs aresulting TS to the demultiplexing section 62. The demultiplexingsection 62 divides the TS input from the tuner 61 into an audio codedsignal, a video coded signal, and a control signal, and outputs theaudio coded signal, the video coded signal, and the control signal tothe audio decoder 63, the video decoder 65, and the controlling section68, respectively.

Further, the demultiplexing section 62 extracts a PCR packet includingtrigger information disposed in the TS, and then outputs the PCR packetto the controlling section 68.

The audio decoder 63 decodes the input audio coded signal, and outputs aresulting audio signal to the audio outputting section 64. The audiooutputting section 64 outputs the input audio signal to a subsequentstage (speaker, for example).

The video decoder 65 decodes the input video coded signal, and outputs aresulting video signal to the trigger detecting section 66 and the videooutputting section 67.

The trigger detecting section 66 always monitors the input video signal,detects trigger information embedded in the video signal, and suppliesthe trigger information to the controlling section 68. Incidentally, thetrigger information can also be transmitted so as to be embedded in thevideo signal of the AV contents corresponding to the digital televisionbroadcast signal.

Thus, when the trigger information is embedded in the video signal andtransmitted from the broadcasting device 11 to the receiving device 30,the trigger detecting section 66 detects the trigger informationembedded in the input video signal.

Suppose in the following that the trigger information is transmitted ina state of being stored in a PCR packet. Description of the case wherethe trigger information is transmitted in a state of being embedded inthe video signal will be omitted as appropriate.

The video outputting section 67 outputs the video signal input from thevideo decoder 65 to a subsequent stage (monitor, for example). Inaddition, the video outputting section 67 combines the video signal(corresponding to the video 42 in FIG. 3, for example) for databroadcasting which video signal is input from the browser 73 with thevideo signal (corresponding to the video 41 in FIG. 3, for example)input from the video decoder 65, and outputs the result to thesubsequent stage.

Further, the video outputting section 67 outputs a video signal forshowing a home page or the like, which video signal is input from thebrowser 73, to the subsequent stage.

Incidentally, an HDMI (High-Definition Multimedia Interface) cable, forexample, can be used for output from the audio outputting section 64 andthe video outputting section 67 to the subsequent stage.

The controlling section 68 controls each block forming the receivingdevice 30 by executing a controlling program recorded in the memory 69in advance. The controlling section 68 also controls the obtainment,execution (starting), event firing, ending and the like of a databroadcasting HTML document for realizing service for data broadcastinginterlocked with a television program on the basis of the triggerinformation input from the demultiplexing section 62 (or the triggerdetecting section 66).

The controlling program executed by the controlling section 68 isrecorded in the memory 69 in advance. The controlling program can beupdated on the basis of the digital television broadcast signal orupdate data obtained via the Internet 20.

In addition, management mode information indicating a management mode isrecorded in the memory 69. The management mode is changed by rewritingthe management mode information. Details of the management mode will bedescribed later with reference to FIG. 13 and FIG. 14. The operatingsection 70 receives various operations from the user, and notifiesoperating signals corresponding to the operations to the controllingsection 68.

When a data broadcasting HTML document is distributed using the digitaltelevision broadcast signal, the recording section 71 retains thedistributed data broadcasting HTML document on a built-in recordingmedium.

The communication I/F 72 connects itself to the server 12 via theInternet 20 under control of the browser 73. Then, under control of thebrowser 73, the communication I/F 72 obtains a data broadcasting HTMLdocument from the server 12 via the Internet 20, and supplies the databroadcasting HTML document to the browser 73.

The communication I/F 72 also connects itself to a server other than theserver 12 via the Internet 20 under control of the browser 73. Then,under control of the browser 73, the communication I/F 72 obtains anHTML document for a home page from the server other than the server 12via the Internet 20, and supplies the HTML document to the browser 73.

The browser 73 under control of the controlling section 68 executes thedata broadcasting HTML document from the communication I/F 72, therebygenerates a video signal for data broadcasting, and supplies the videosignal for data broadcasting to the video outputting section 67.

In addition, the browser 73 under control of the controlling section 68executes the HTML document for the home page from the communication I/F72, thereby generates a video signal for showing the home page and thelike, and supplies the video signal to the video outputting section 67.

[Details of Trigger Information]

FIG. 6 shows a concept in a case where trigger information is stored andtransmitted in PCR packets of a TS. As shown in FIG. 6, not all PCRpackets store trigger information, but trigger information is stored inPCR packets only in appropriate timing for interlocking with AV contentscorresponding to a television program.

Incidentally, depending on contents of trigger information, triggerinformation of the same contents may be transmitted a plurality of timesin consideration of a case where the trigger information is not receivedby the receiving device 30.

FIG. 7 shows a position where trigger information is stored in a PCRpacket. The PCR packet has PCR stored in the adaptation_field of a TSpacket. The trigger information (TriggerInfo_descriptor) is stored intransport_private_data_byte following the PCR. Incidentally, whentrigger information is stored, the transport_private_data_flag ofVarious_flags provided in front of the PCR is set at one.

FIG. 8 shows an example of information items included in triggerinformation.

A trigger ID is information for identifying the trigger information inquestion. When trigger information of the same contents is transmitted aplurality of times, the trigger ID of each piece of trigger informationis identical. A trigger type indicates that the trigger information inquestion is one of an application start (giving an instruction to obtainand execute (start) a data broadcasting HTML document), an applicationend (giving an instruction to end the data broadcasting HTML documentbeing executed), an application event (giving an instruction to fire anevent (update of display contents or the like) in the data broadcastingHTML document being executed), and a pre-cache (giving an instructiononly to obtain the data broadcasting HTML document).

An application ID is information for identifying the data broadcastingHTML document corresponding to the trigger information in question. Anapplication type is information indicating the type (html) of the databroadcasting HTML document corresponding to the trigger information inquestion. A provider ID is information for identifying a provider(broadcasting station or the like) performing service for execution ofthe data broadcasting HTML document corresponding to the triggerinformation in question. An application URL (Uniform Resource Locator)is the URL of a destination from which to obtain the data broadcastingHTML document in the case where the trigger type is the applicationstart or the pre-cache. A stored application ID is described only whenspecifying the stored (already obtained) data broadcasting HTML documentto be started without instantly obtaining the data broadcasting HTMLdocument in the case where the trigger type is the application start.

An automatic start flag is described in the case where the trigger typeis the application start. The automatic start flag is set on or off.When the automatic start flag is on, an automatic start is made (thedata broadcasting HTML document is started automatically). When theautomatic start flag is off, a manual start is made (the user isprompted to perform an operation input, and a start is made in responseto the performance of the operation input).

An application end time is information indicating a time to end the databroadcasting HTML document when the trigger information whose triggertype is the application end cannot be received.

An application name is the name of service (realized by the databroadcasting HTML document) for data broadcasting to be presented to theuser when the automatic start flag indicates the manual start, forexample. An event ID is information for identifying an event when thetrigger type is the application event. Incidentally, the triggerinformation does not always include all of the above-described items,but includes only necessary items in the timing of the triggerinformation.

FIG. 9 shows an example of syntax of the trigger information.Incidentally, the syntax of the trigger information is arbitrary, and isnot limited to FIG. 9.

[Trigger Information Corresponding Process]

Description will next be made of a trigger information correspondingprocess performed when the receiving device 30 receives triggerinformation.

FIG. 10 is a flowchart of assistance in explaining the triggerinformation corresponding process. This trigger informationcorresponding process is repeatedly performed while the user is viewinga television program, that is, while a digital television broadcastsignal is received.

In step S1, the controlling section 68 stands by until a PCR packetincluding trigger information is received on the basis of input from thedemultiplexing section 62. When a PCR packet including triggerinformation is received, the controlling section 68 advances the processto step S2.

In step S2, the controlling section 68 extracts the trigger informationfrom the received PCR packet, and determines whether a process from stepS3 on down has already been performed for the trigger information on thebasis of the trigger information. When it is determined that the processfrom step S3 on down has already been performed, the process is returnedto step S1 to repeat the process from step S1 on down. When it isdetermined that the process from step S3 on down has not been performedfor the trigger information, on the other hand, the process is advancedto step S3.

In step S3, the controlling section 68 determines whether the triggertype of the trigger information in question is the application start,the application event, the application end, or the pre-cache.

When it is determined in step S3 that the trigger type of the triggerinformation in question is the application start, the process isadvanced to step S4.

In step S4, the controlling section 68 determines whether a storedapplication ID is specified in the trigger information in question andwhether the data broadcasting HTML document corresponding to the triggerinformation is already stored in the recording section 71.

When the determination is made in the negative in step S4, the processis advanced to step S5. In step S5, the controlling section 68 controlsthe browser 73 so as to make the browser 73 access the server 12corresponding to the application URL of the trigger information andobtain the data broadcasting HTML document corresponding to theapplication ID of the trigger information. When the corresponding databroadcasting HTML document is already obtained from the server 12corresponding to the above URL and pre-cached in step S14 to bedescribed later, the process of step S5 is skipped, and the databroadcasting HTML document is used in a process from step S7 on down.The process is thereafter advanced to step S7.

When it is determined in step S4 that the stored application ID isspecified in the trigger information in question and that the databroadcasting HTML document corresponding to the trigger information isalready stored in the recording section 71, the process is advanced tostep S6. In step S6, the controlling section 68 controls the browser 73so as to make the browser 73 read the data broadcasting HTML documentcorresponding to the stored application ID of the trigger informationfrom the recording section 71. The process is thereafter advanced tostep S7.

In step S7, the controlling section 68 determines whether the automaticstart flag of the trigger information indicates the automatic start.

When it is determined in step S7 that the automatic start flag of thetrigger information does not indicate the automatic start (that is, theautomatic start flag of the trigger information indicates the manualstart), the process is advanced to step S8. In step S8, the browser 73prompts the user for an operation of starting (operation of executing)the data broadcasting HTML document by displaying for example “Execute(application name)?” on a screen under control of the controllingsection 68. When it is determined in step S9 that the starting operationis input from the user in response to the prompt display, the process isadvanced to step S11. In step S11, the browser 73 starts (executes) thedata broadcasting HTML document obtained in step S5 or read in step S6under control of the controlling section 68. Thereafter, the process isreturned to step S1, and the process from step S1 on down is repeated.

Incidentally, when it is determined in step S9 that the startingoperation is not input from the user after the prompt display in stepS8, and it is determined in step S10 that a predetermined time haspassed without the starting operation being input from the user, theprocess is returned to step S1, and the process from step S1 on down isrepeated.

When it is determined in step S7 that the automatic start flag of thetrigger information indicates the automatic start, the process isadvanced to step S11. In step S11, the browser 73 starts the databroadcasting HTML document obtained in step S5 or read in step S6 undercontrol of the controlling section 68. Thereafter, the process isreturned to step S1, and the process from step S1 on down is repeated.

When it is determined in step S3 that the trigger type of the triggerinformation in question is the application event, the process isadvanced to step S12. In step S12, the controlling section 68 controlsthe browser 73 so as to fire (execute) an event corresponding to theevent ID of the trigger information in the data broadcasting HTMLdocument being executed only when the application ID of the triggerinformation in question and the application ID of the data broadcastingHTML document being executed coincide with each other. Thereafter, theprocess is returned to step S1, and the process from step S1 on down isrepeated.

When it is determined in step S3 that the trigger type of the triggerinformation in question is the application end, the process is advancedto step S13. In step S13, the controlling section 68 controls thebrowser 73 so as to end the data broadcasting HTML document beingexecuted only when the application ID of the trigger information inquestion and the application ID of the data broadcasting HTML documentbeing executed coincide with each other. Thereafter, the process isreturned to step S1, and the process from step S1 on down is repeated.

Incidentally, even in a case where the trigger information whose triggertype is the application end is not received, the data broadcasting HTMLdocument being executed is ended when a present time reaches theapplication end time described in the trigger information at the time ofstarting the data broadcasting HTML document being executed.

When it is determined in step S3 that the trigger type of the triggerinformation in question is the pre-cache, the process is advanced tostep S14. In step S14, the controlling section 68 controls the browser73 to make the browser 73 access the server 12 corresponding to theapplication URL of the trigger information, obtain the data broadcastingHTML document corresponding to the application ID of the triggerinformation, and store (pre-cache) the data broadcasting HTML documentin storing means such as a cache memory or the like included in thebrowser 73. Thereafter, the process is returned to step S1, and theprocess from step S1 on down is repeated.

When the trigger type is the pre-cache as in step S14, the correspondingdata broadcasting HTML document can be obtained before the broadcastingtime of the television program desired to be interlocked. Thereby thecorresponding data broadcasting HTML document can be executed at thesame time as a start of the television program desired to beinterlocked. This concludes the description of the trigger informationcorresponding process.

[Example of Screen Display when Data Broadcasting HTML Document isExecuted]

Next, FIG. 11 shows transitions of a screen when a data broadcastingHTML document is executed so as to be interlocked with the progress of atelevision program in a case where the automatic start flag of triggerinformation is off (manual start).

When trigger information whose trigger type is the application start andwhose automatic start flag is off (manual start) is received while theuser is viewing a television program, a corresponding data broadcastingHTML document (corresponding to HTML in FIG. 11) is obtained. Next, adisplay (corresponding to “App Start?” in FIG. 11) prompting the userfor an operation of starting the data broadcasting HTML document isdisplayed in a state of being superimposed on the video of thetelevision program. When the user inputs the starting operation inresponse to the prompt, the data broadcasting HTML document is executed,and screen display becomes for example the video 43 obtained bycombining the video 41 of the television program with the video 42 ofdata broadcasting contents as shown in FIG. 3.

When trigger information whose trigger type is the application event isreceived in a state of the data broadcasting HTML document beingexecuted, an event corresponding to the event ID of the triggerinformation is fired in the data broadcasting HTML document beingexecuted. Thereby, an area (for example an area displaying the video 42in FIG. 3) displaying the data broadcasting contents in the screendisplay is changed to video corresponding to the event ID of the triggerinformation (for example changed from first information to secondinformation or from the second information to third information).

When trigger information whose trigger type is the application end isthereafter received, the data broadcasting HTML document being executedis ended, and only the video 41 of the television program is displayedon the entire screen.

[Another Example of Screen Display when Data Broadcasting HTML Documentis Executed]

Incidentally, a data broadcasting HTML document executed so as to beinterlocked with the progress of a television program does notnecessarily involve screen display. When such a data broadcasting HTMLdocument is used, the data broadcasting HTML document can be executedwithout being noticed by the user of the receiving device 30. Such adata broadcasting HTML document can be applied to a case of surveyingthe audience rating of a television program, for example. Specifically,when whether a television program is viewed is recorded so as tocorrespond to trigger information whose trigger type is the applicationevent, and a result of the recording is notified to a predeterminedserver or the like in predetermined timing, the audience rating of thetelevision program can be surveyed at intervals of transmission of thetrigger information whose trigger type is the application event.

FIG. 12 shows transitions of a screen when a data broadcasting HTMLdocument not involving screen display is executed so as to beinterlocked with the progress of a television program in a case wherethe automatic start flag of trigger information is on (automatic start).

When trigger information whose trigger type is the application start andwhose automatic start flag is on (automatic start) is received while theuser is viewing a television program, a corresponding data broadcastingHTML document is obtained and executed. However, screen display is notchanged with only the video 41 of the television program displayed.

When trigger information whose trigger type is the application event isreceived in a state of the data broadcasting HTML document beingexecuted, an event corresponding to the event ID of the triggerinformation is fired in the data broadcasting HTML document beingexecuted. Also in this case, screen display is not changed with thevideo 41 of the television program displayed.

When trigger information whose trigger type is the application end isthereafter received, the data broadcasting HTML document being executedis ended.

[Life Cycle of Data Broadcasting Contents]

Next, FIG. 13 shows an example of a life cycle of a data broadcastingHTML document.

When trigger information whose trigger type is the application start isreceived in a case where a data broadcasting HTML document to beobtained and executed by the receiving device 30 is in a TDO stopoperation state (corresponding to TDO Stop in FIG. 13), that is, in acase where the receiving device 30 has not obtained the databroadcasting HTML document, a transition is made from the TDO stopoperation state to a TDO active operation state (corresponding to TDOActive in FIG. 13), and the data broadcasting HTML document is obtainedfrom the server 12.

Then, a display prompting the user for an operation of starting the databroadcasting HTML document is displayed in a state of being superimposedon the video of a television program. When the user inputs the startingoperation in response to the prompt, the data broadcasting HTML documentis started, and screen display becomes for example the video 43 obtainedby combining the video 41 of the television program with the video 42 ofdata broadcasting contents as shown in FIG. 3.

In the TDO active operation state, the receiving device 30 can perform aspecific process to display the video 42 of the data broadcastingcontents by the obtained data broadcasting HTML document. That is, themanagement mode of the receiving device 30 in the TDO active operationstate is “Broadcast managed,” allowing the specific process using thedata broadcasting HTML document obtained from the server 12 managed onthe broadcaster side.

When trigger information whose trigger type is the application event isreceived in the TDO active operation state, an event corresponding tothe event ID of the trigger information is fired in the databroadcasting HTML document being executed.

Incidentally, when trigger information whose trigger type is theapplication end is received or an application end time has arrived inthe TDO active operation state, a transition is made from the TDO activeoperation state to the TDO stop state, and the obtained databroadcasting HTML document is discarded, for example.

In addition, when trigger information whose trigger type is thepre-cache is received in the TDO stop operation state, a transition ismade from the TDO stop operation state to a TDO pre-cache readyoperation state, and the corresponding data broadcasting HTML documentis obtained and pre-cached.

When trigger information whose trigger type is the application start isreceived in the TDO pre-cache ready operation state, a transition ismade from the TDO pre-cache ready operation state to the TDO activeoperation state. Then, the pre-cached data broadcasting HTML document isstarted in the TDO active operation state.

In addition, when a button or the like provided with a link to a homepage of an automobile or the like is pressed by a user operation in theTDO active operation state, a transition is made from the TDO activeoperation state to a Web active operation state (corresponding to WebActive in FIG. 13). Then, in the Web active operation state, an HTMLdocument for the home page from a server not managed on the broadcasterside (server other than the server 12) is executed for example todisplay the home page of the automobile or the like.

In the Web active operation state, the receiving device 30 cannotperform a specific process by the obtained HTML document for the homepage. That is, the management mode of the receiving device 30 in the Webactive operation state is “Broadcast unmanaged,” not allowing a specificprocess using the HTML document for the home page obtained from a servernot managed on the broadcaster side (server other than the server 12).

In the TDO active operation state (the management mode is set at“Broadcast managed”), a specific process such for example as readingarea information already recorded in the receiving device 30 needs to beallowed in order to provide service for data broadcasting.

In the Web active operation state (the management mode is set at“Broadcast unmanaged”), on the other hand, the specific process needs tobe prevented from being performed in order to prevent the areainformation already recorded in the receiving device 30 from beingillegally read and leaked.

Accordingly, in the receiving device 30, as described above, when anHTML document to be executed is obtained from the server 12 managed onthe broadcaster side, the management mode is set at “Broadcast managed”to allow the specific process.

Conversely, in the receiving device 30, when an HTML document to beexecuted is obtained from a server not managed on the broadcaster side,the management mode is set at “Broadcast unmanaged” so as not to allowthe specific process.

[Management Mode]

FIG. 14 shows an example in which a transition is made from the TDOactive operation state to the Web active operation state, that is, themanagement mode is set from “Broadcast managed” to “Broadcast unmanaged”while events are sequentially fired in the TDO active operation state.

Incidentally, suppose that in a data broadcasting HTML document, a URLfor identifying the HTML document to be executed to update the video 42of data broadcasting contents is described in association with an eventID.

Thereby, in response to reception of trigger information whose triggertype is the application event, an HTML document “a1.html” for executingan event identified by an event ID included in the trigger informationis obtained and executed on the basis of an URL“http://www.a.com/a1.html” described in the data broadcasting HTMLdocument.

Further, in response to reception of new trigger information whosetrigger type is the application event, an HTML document “a2.html” forexecuting an event identified by an event ID included in the triggerinformation is obtained and executed on the basis of an URL“http://www.a.com/a2.html” described in the data broadcasting HTMLdocument. Thereby, the display of the video 42 is sequentially updatedto video displayed by executing the HTML document “a1.html” and to videodisplayed by executing the HTML document “a2.html.”

In addition, suppose that a link destination “http://www.b.com/b1.html”of an HTML document “b1.html” executed when a user operation ofselecting the video of a driver displayed in the video 42 of databroadcasting contents (FIG. 3) is performed is described in the databroadcasting HTML document.

When the user operation of selecting the video of the driver displayedin the video 42 (FIG. 3) is performed in the TDO active operation state,a transition is made from the TDO active operation state to the Webactive operation state.

In this case, the receiving device 30 in the Web active operation stateobtains and executes the HTML document “b1.html” for a home page from aserver not managed on the broadcaster side on the basis of the linkdestination “http://www.b.com/b1.html.”

As shown in FIG. 14, when HTML documents to be executed are obtainedfrom the server 12 and executed in the TDO active operation state, forexample, the HTML documents (a1.html and a2.html in this case) are eachobtained from the server 12 managed on the broadcaster side(http://www.a.com/ in this case).

In addition, HTML documents to be executed in the Web active operationstate (b1.html in this case), for example, are obtained from a servernot managed on the broadcaster side (http://www.b.com/ in this case).

As described above, the specific process is also allowed when an HTMLdocument is obtained from the server 12 and executed, and the specificprocess needs to be prevented from being performed when an HTML documentis obtained from a server other than the server 12 and executed.

Accordingly, the receiving device 30 determines whether an HTML documentto be executed is obtained from the server 12 according to whether thedomain name of the server 12 managed on the broadcaster side coincideswith the domain name of a destination from which the HTML document to beexecuted is obtained.

Incidentally, the receiving device 30 regards the domain name (www.a.comin this case) of a destination from which an HTML document is obtainedfirst in realizing service for data broadcasting, that is, a databroadcasting HTML document is obtained as the domain name of the server12 managed on the broadcaster side, and determines whether an HTMLdocument to be executed is obtained from the server 12.

The receiving device 30 sets the management mode to “Broadcast managed”or “Broadcast unmanaged” on the basis of whether the domain name of anHTML document to which a transition is made is the domain name of theserver 12 managed on the broadcaster side.

Then, the receiving device 30 allows the specific process when themanagement mode is “Broadcast managed” (in the case of the TDO activeoperation state), and prevents the specific process from being performedwhen the management mode is “Broadcast unmanaged” (in the case of theWeb active operation state).

Incidentally, while the receiving device 30 regards the domain name of adestination from which a data broadcasting HTML document is obtained inrealizing service for data broadcasting as the domain name of the server12 managed on the broadcaster side, the receiving device 30 may retainthe domain name of a server managed by each broadcaster corresponding toeach received channel in advance.

Then, the receiving device 30 may select a domain name corresponding toa received channel from the domain names retained in advance, and regardthe domain name as the domain name of the server managed on thebroadcaster side.

In addition, for example, while the receiving device 30 uses a domainname to determine whether an HTML document to be executed is obtainedfrom the server 12, any information may be used as long as theinformation uniquely indicates the server as the obtaining destination.That is, for example, the receiving device 30 can determine whether anHTML document to be executed is obtained from the server 12 using notonly the domain name but also a MAC (Media Access Control) address, anIP (Internet Protocol) address, or the like.

[Details of Management Mode Setting Process]

A management mode setting process in which the receiving device 30 setsthe management mode on the basis of the domain name of a destinationfrom which an HTML document is obtained will next be described withreference to a flowchart of FIG. 15.

This management mode setting process is started when a data broadcastingHTML document is started in step S11 in FIG. 10, for example.

In step S31, the controlling section 68 obtains the domain name of adestination from which the started data broadcasting HTML document isobtained.

Specifically, when the started data broadcasting HTML document isobtained on the basis of the application URL of trigger information instep S5 or step S14 in FIG. 10, for example, the controlling section 68obtains the domain name of the destination (server 12) from which thestarted data broadcasting HTML document is obtained on the basis of theapplication URL of the trigger information.

When the started data broadcasting HTML document is read and obtainedfrom the recording section 71 in step S6 in FIG. 10, for example, thecontrolling section 68 controls the browser 73 so as to make the browser73 obtain the domain name of the server 12 retaining the started databroadcasting HTML document from the recording section 71 and supply thedomain name of the server 12 to the controlling section 68. Thecontrolling section 68 thereby obtains the domain name. Incidentally,suppose that when the data broadcasting HTML document is recorded in therecording section 71, the domain name of the server 12 retaining thedata broadcasting HTML document is recorded in association with the databroadcasting HTML document.

In step S32, the controlling section 68 controls the browser 73 so as tomake the browser 73 operate in the management mode “Broadcast managed”in which the specific process can be performed. That is, the controllingsection 68 controls the execution of the HTML document in the browser 73so as to allow the specific process to be performed by executing theHTML document (does not limit performing the specific process).

In step S33, the controlling section 68 determines whether a documenttransition according to an HTML document has occurred on the basis ofinput trigger information, an operating signal from the operatingsection 70, or the like. The controlling section 68 waits for a documenttransition to occur, and then advances the process to step S34.

In step S34, the controlling section 68 determines whether the HTMLdocument as transition destination is obtained from the server 12managed on the broadcaster side on the basis of whether the domain nameof a destination from which the HTML document as transition destinationis obtained coincides with the domain name already obtained in theprocess of step S31. When it is determined in step S34 that the HTMLdocument as transition destination is obtained from the server 12, theprocess is returned to step S33, and a similar process is thereafterperformed with the browser 73 operated in the management mode “Broadcastmanaged.”

When it is determined in step S34 that the HTML document as transitiondestination is not obtained from the server 12, the process is advancedto step S35, where the controlling section 68 controls the browser 73 soas to make the browser 73 operate in the management mode “Broadcastunmanaged” in which the specific process cannot be performed. That is,the controlling section 68 controls the execution of the HTML documentin the browser 73 so as not to allow the specific process to beperformed by executing the HTML document (limits performing the specificprocess).

In this case, in step S35, the browser 73 cannot perform the specificprocess, and for example executes an HTML document for a home page asHTML document as transition destination. Incidentally, suppose that thedata broadcasting HTML document is ended on the basis of triggerinformation whose trigger type is the application end, for example,while the HTML document for the home page is executed.

Thereafter, in step S36, the controlling section 68 determines whetherto start a new data broadcasting HTML document, and waits to determinethat a new data broadcasting HTML document is to be started. Thecontrolling section 68 then returns the process to step S31, and asimilar process is thereafter repeated. Specifically, for example, thecontrolling section 68 determines whether trigger information forstarting a new data broadcasting HTML document is input, and waits todetermine that the trigger signal is input. The controlling section 68then returns the process to step S31, and a similar process isthereafter repeated.

As described above, in the management mode transition process, themanagement mode is set at “Broadcast managed” when the domain name of adata broadcasting HTML document and the domain name of an HTML documentas transition destination coincide with each other, and the managementmode is set at “Broadcast unmanaged” when the domain name of a databroadcasting HTML document and the domain name of an HTML document astransition destination do not coincide with each other.

When the management mode is set at “Broadcast managed,” for example aprocess of reading area information of the user which area informationis already stored in the receiving device 30 or the like is allowed tobe performed by executing a data broadcasting HTML document. When themanagement mode is set at “Broadcast unmanaged,” the reading process orthe like is prevented from being performed by executing an HTML documentfor a home page as a process unintended by the user.

Thus, the process unintended by the user can be prevented from beingperformed even when an HTML document for a home page created by amalicious third party is obtained and executed.

2. Example of Modification

In the present embodiment, as shown in FIG. 13, the operation states ofa data broadcasting HTML document are four operations states, that is,the TDO stop operation state, the TDO pre-cache ready operation state,the TDO active state, and the Web active state. However, as shown inFIG. 16, for example, the operation states of a data broadcasting HTMLdocument can be five operation states including a newly added TDOsuspend operation state (corresponding to TDO Suspend in FIG. 16).

In this case, as shown in FIG. 17, suspend is newly added as the triggertype of trigger information, and the trigger type of trigger informationindicates one of the application start, the application end, theapplication event, the pre-cache, and the suspend.

In FIG. 16, when trigger information whose trigger type is the suspendis received in the TDO active operation state, the operation state of acorresponding data broadcasting HTML document makes a transition to theTDO suspend operation state. In this case, because the operation stateof a corresponding data broadcasting application makes a transition tothe TDO suspend operation state, another data broadcasting HTML documentcan be set in the TDO active operation state and executed.

When trigger information whose trigger type is the application start isreceived in the TDO suspend operation state, the corresponding databroadcasting HTML document makes a transition to the TDO activeoperation state. Thereby, an event can be fired in the data broadcastingHTML document. At this time, the other data broadcasting HTML documentmakes a transition from the TDO active operation state to the TDOsuspend operation state.

The series of processes described above can be carried out not only byhardware but also by software. When the series of processes is to becarried out by software, a program constituting the software isinstalled from a program recording medium onto a computer incorporatedin dedicated hardware or for example a general-purpose personal computerthat can perform various functions by installing various programsthereon.

[Example of Configuration of Computer]

FIG. 18 is a block diagram showing an example of hardware configurationof a computer performing the series of processes described above by aprogram.

In this computer 100, a CPU (Central Processing Unit) 101, a ROM (ReadOnly Memory) 102, and a RAM (Random Access Memory) 103 areinterconnected by a bus 104.

The bus 104 is further connected with an input-output interface 105. Theinput-output interface 105 is connected with an inputting section 106formed by a keyboard, a mouse, a microphone and the like, an outputtingsection 107 formed by a display, a speaker and the like, a storingsection 108 formed by a hard disk, a nonvolatile memory and the like, acommunicating section 109 formed by a network interface and the like,and a drive 110 for driving removable media 111 such as a magnetic disk,an optical disk, a magneto-optical disk, a semiconductor memory and thelike.

In the computer configured as described above, the CPU 101 for exampleloads a program stored in the storage section 108 into the RAM 103 viathe input-output interface 105 and the bus 104, and then executes theprogram. Thereby the series of processes described above is performed.

It is to be noted that the program executed by the computer may be aprogram in which processing is performed in time series in the orderdescribed in the present specification or may be a program in whichprocessing is performed in parallel or in necessary timing such as at atime of a call being made, for example.

In addition, the program may be processed by one computer, or may besubjected to distributed processing by a plurality of computers.Further, the program may be transferred to a remote computer andexecuted by the remote computer.

In addition, in the present specification, a system refers to anapparatus as a whole formed by a plurality of devices.

It is to be noted that embodiments of the present invention are notlimited to the foregoing embodiments, and that various changes can bemade without departing from the spirit of the present invention.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. (canceled)
 2. A method of a reception apparatus for executing anapplication program, the method comprising: receiving a digitaltelevision broadcast signal including a television program and a firsttrigger associated with the television program, the first triggerincluding a location of the application program associated with thetelevision program; outputting the television program for display to auser; retrieving the application program based on the location includedin the first trigger while the television program is outputted fordisplay to the user; executing, by circuitry of the reception apparatus,the application program in response to a second trigger included in thedigital television broadcast signal, the application program beingexecuted so as to be synchronized with the progress of the televisionprogram; receiving a third trigger included in the digital televisionbroadcast signal that indicates a predetermined event to be executed bythe application program; when the application program being executed bythe circuitry is determined to be of a managed type, permitting theapplication program to perform a function associated with thepredetermined event; and when the application program being executed bythe circuitry is determined to be of an unmanaged type, prohibiting theapplication program from performing the function associated with thepredetermined event.
 3. The method according to claim 2, wherein theapplication program is configured to concurrently display additionalcontent with the television program.
 4. The method according to claim 2,wherein the function associated with the predetermined event is to readpredetermined information stored in a memory of the reception apparatus.5. The method according to claim 2, wherein the function associated withthe predetermined event is to provide predetermined information storedin a memory of the reception apparatus to an external device.
 6. Themethod according to claim 2, wherein the third trigger includes an eventidentifier that identifies the predetermined event.
 7. The methodaccording to claim 2, wherein the step of retrieving the applicationprogram comprises: retrieving the application program from an Internetserver.
 8. A non-transitory computer-readably storage medium storinginstructions which when executed by a computer cause the computer toperform a method for executing an application program, the methodcomprising: receiving a digital television broadcast signal including atelevision program and a first trigger associated with the televisionprogram, the first trigger including a location of the applicationprogram associated with the television program; outputting thetelevision program for display to a user; retrieving the applicationprogram based on the location included in the first trigger while thetelevision program is outputted for display to the user; executing, bycircuitry of the reception apparatus, the application program inresponse to a second trigger included in the digital televisionbroadcast signal, the application program being executed so as to besynchronized with the progress of the television program; receiving athird trigger included in the digital television broadcast signal thatindicates a predetermined event to be executed by the applicationprogram; when the application program being executed by the circuitry isdetermined to be of a managed type, permitting the application programto perform a function associated with the predetermined event; and whenthe application program being executed by the circuitry is determined tobe of an unmanaged type, prohibiting the application program fromperforming the function associated with the predetermined event.
 9. Thenon-transitory computer-readable storage medium according to claim 8,wherein the application program is configured to concurrently displayadditional content with the television program.
 10. The non-transitorycomputer-readable storage medium according to claim 8, wherein thefunction associated with the predetermined event is to readpredetermined information stored in a memory of the reception apparatus.11. The non-transitory computer-readable storage medium according toclaim 8, wherein the function associated with the predetermined event isto provide predetermined information stored in a memory of the receptionapparatus to an external device.
 12. The non-transitorycomputer-readable storage medium according to claim 8, wherein the thirdtrigger includes an event identifier that identifies the predeterminedevent.
 13. The non-transitory computer-readable storage medium accordingto claim 8, wherein the step of retrieving the application programcomprises: retrieving the application program from an Internet server.14. A reception apparatus, comprising: circuitry configured to receive adigital television broadcast signal including a television program and afirst trigger associated with the television program, the first triggerincluding a location of an application program associated with thetelevision program; output the television program for display to a user;retrieve the application program based on the location included in thefirst trigger while the television program is outputted for display tothe user; execute the application program in response to a secondtrigger included in the digital television broadcast signal, theapplication program being executed so as to be synchronized with theprogress of the television program; receive a third trigger included inthe digital television broadcast signal that indicates a predeterminedevent to be executed by the application program; when the applicationprogram being executed by the circuitry is determined to be of a managedtype, permit the application program to perform a function associatedwith the predetermined event; and when the application program beingexecuted by the circuitry is determined to be of an unmanaged type,prohibit the application program from performing the function associatedwith the predetermined event.
 15. The reception apparatus according toclaim 14, wherein the application program is configured to concurrentlydisplay additional content with the television program.
 16. Thereception apparatus according to claim 14, wherein the functionassociated with the predetermined event is to read predeterminedinformation stored in a memory of the reception apparatus.
 17. Thereception apparatus according to claim 14, wherein the functionassociated with the predetermined event is to provide predeterminedinformation stored in a memory of the reception apparatus to an externaldevice.
 18. The reception apparatus according to claim 14, wherein thethird trigger includes an event identifier that identifies thepredetermined event.
 19. The reception apparatus according to claim 14,wherein the circuitry is further configured to retrieve the applicationprogram from an Internet server.